env: delete selected vars not present in imported env

[u-boot] / README

diff --git a/README b/README
index 67dc444bd4d0bbe92d2cefcf45b220d079f98c37..fb9d904a2eab0855879feb14f11359b73f0f5e60 100644 (file)
--- a/README
+++ b/README
@@ -374,6 +374,15 @@ The following options need to be configured:
                Defines the string to utilize when trying to match PCIe device
                tree nodes for the given platform.
 
+               CONFIG_SYS_PPC_E500_DEBUG_TLB
+
+               Enables a temporary TLB entry to be used during boot to work
+               around limitations in e500v1 and e500v2 external debugger
+               support. This reduces the portions of the boot code where
+               breakpoints and single stepping do not work.  The value of this
+               symbol should be set to the TLB1 entry to be used for this
+               purpose.
+
 - Generic CPU options:
                CONFIG_SYS_BIG_ENDIAN, CONFIG_SYS_LITTLE_ENDIAN
 
@@ -2140,6 +2149,13 @@ The following options need to be configured:
 
                Timeout waiting for an ARP reply in milliseconds.
 
+               CONFIG_NFS_TIMEOUT
+
+               Timeout in milliseconds used in NFS protocol.
+               If you encounter "ERROR: Cannot umount" in nfs command,
+               try longer timeout such as
+               #define CONFIG_NFS_TIMEOUT 10000UL
+
 - Command Interpreter:
                CONFIG_AUTO_COMPLETE
 
@@ -2220,6 +2236,20 @@ The following options need to be configured:
                the environment like the "source" command or the
                boot command first.
 
+               CONFIG_ENV_VARS_UBOOT_CONFIG
+
+               Define this in order to add variables describing the
+               U-Boot build configuration to the default environment.
+               These will be named arch, cpu, board, vendor, and soc.
+
+               Enabling this option will cause the following to be defined:
+
+               - CONFIG_SYS_ARCH
+               - CONFIG_SYS_CPU
+               - CONFIG_SYS_BOARD
+               - CONFIG_SYS_VENDOR
+               - CONFIG_SYS_SOC
+
 - DataFlash Support:
                CONFIG_HAS_DATAFLASH